Chain-stitch sewing-machine



G. S. GATCHELL.

CHAIN STITCH szwms MACHENE.

APPLICATION FILED MAR-18,1918- 1,319,469.. Patented Oct. 21,1919.

4 SHEETS-SHEET I. Q N M \NVENTOR ATTORNEY m5 COLUMEM PLANbuR/WH 60., WASHINGTON. u. c.

WITNE SSE S G. S. GATCHELL.

CHAIN STITCH SEWING MACHINE.

APPLICATION FILED MAR, 18. I918. 1319,46 Patenmd Oct. 21,1919.

4 SI'IEETSSHEET 2.

Ii. I EQIf IiIIM I I H IJ Um INVENTOR 5W WITNESSES G. S. GATCHELL.

CHAIN STITCH SEWING MACHINE.

APPLlCATlON FILED MAR. 18.1918.

Patented Out; 21, 1919.

4 SHEETS-SHEET 3.

flu I M 1 Wt WITNESSES wW.M

INVENTOR TTORNEY THE cowMmA PLANOGRMII cm, WASHINGTON, u c

G. S. GATCHELL.

CHAIN STITCH SEWING MACHINE.

APPLICATION FILED MAR. I8. I9I8.

Parented Oct. 21,1919.

Iymww.

4 SHEETS-SHEET 4- ATTORNEY INVENTOR l i/ f lm, wew

WITNESSES UNITED STATES PATENT OFFICE.

GEORGE S. GATCI-IELL, 0F ROSELLE PARK, NEW' JERSEY, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented Oct. 21, 1919.

Original application filed August 10, 1917, Serial No. 185,446. Divided and this appIieation filed March 18, 1918. Serial No. 223,110.

To all whom it may concern Be it known that I, Greener. S. GATGIIELL, a citizen of the United States, residing at Roselle Park, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Chain- Stitch Sewing-h lachines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to chain-stitch sewing machines of the so-called cylinder oed type adapted to sew up tubular worksuch as the arms and legs of garments and has for an object to improve the operative characteristics of the stitch-forming mechanism of such a machine without increasing the circumference of the work-arm in which the looper is customarily housed.

Further objects of the invention will ap pear from the following description and claims- In chain-stitch machines having a plurality of needles set in a plane crossing the line of feed and the usual short-radius looper cooperating with the needles to form stitches, there is a great tendency for the needle-loops to crowd together on the looperblade rather than remain properly'spaced apart to permit passage of the needles to one side of their respective loops as is es sential to the proper formation of stitches.

Heretofore, attempts to flatten out the path of the looper in cylinder-bed machines by increasing the loopers radius of oscilla tion have been accompanied either by an increase in the circumference of the workarm or by an increase in the displacement of the path of the looperblade below thev needle-holes in the throat-plate.

An increase in the circumference of the work-arm is undesirable as it unfits the machine for use in sewing up tubular work of the smaller sizes and an increase in the dis-- tance of the looper-path below the needle holes in the throat-plate renders the stitchforming mechanism less certain in its oporation for the reason that an increased dip of the needles below the throat-plate must be provided to insure formation of needle loops in the path of the advancing looper. The longer these needle-loops are, the greater their likelihood to become entangled with one another or to twist sidewise and escape seizure by the leoper. Furthermore stantially when seized by the looper, it is difficult to maintain these long needle-loops .in properly spaced relation lengthwise of the looperblade since the greater their length, the greater their tendency to crowd together on the looper. Another disadvantage incident to an increase in the radius of oscillation of a looper within a work-arm of circular section lies in the necessity for shortening the stroke of the looper and consequently dccreasing the amount of thread carried into the needle-loops by the looper below the amount required to properly form the stitch.

In the present machine, in order to secure a material increase in the radius of oscillation of the looper and thereby more nearly approximate a right line movement of the looper into and out of the needle-loops, the work-arm is formed with two intersecting angularly arranged fiat sides and an upper curved side, whereby the worlearm is subsector-shaped in cross-section. The looper-supporting shaft is arranged lengthwise of and within the work-arm and as closely as practicable to the apex of the angle formed by the flat sides of the worl:- arm. The curved side of the work-arm is substantially concentric with the loopershaft and the path of the looper-blade, so that the latter may move as closely as possible to the under side of the throat-plate.

The machine is equipped with feeding mechanism of the differential type including main and auxiliary feed-bars arranged withinnnd lengthwise of the present novel form of work-arm and above the loopershaft. At its free end the hollow work-arm supports a throat-plate V projecting forwardly thereof and forming the sole sup port for a removable end-cap which surrounds and protects the looper.

In the accompanying drawings Figure 1 is a right side elevation of the machine, partly in section. Fig. 2 is a similar view from the left side of the machine. Fig. 3 is a front elevation of the machine with the looper inclosing end-cap in section. Fig. 4 is a rear end elevation of the machine, partly in section, to expose the mechanism housed within the standard. Fig. 5 is a top plan view of the machine with the inclineddriving shaft for t ie take-up omitted. Fi 6 is a horizontal section through the standard above the plane of the work-arm and showing the work-arm in plan. Figs. 7 and S are cross-sections through the work-arm on the lines 77, 88, respectively, Fig. (3. Fig. 9 is a bottom plan view of the throatplate. Fig. 10 is a transverse vertical section through the throat-plate on the line 99, of Fig. 9. Fig. 11 is a perspective view of a detail of the looper-actuating mechanism. Fig. 12 is an enlarged plan view of the free end portion of the workarm.

The present invention is shown incorporated in a machine more fully represented in my copending application Serial No.1 85,a &6, filed Aug. 10, 1917, of which this application is a division. The machine frame is formed with a base 1 from which rises the standard 2 carrying the overhanging bracket-arm 3 terminating in the hollow head 4. Secured to the standard 2 is the flanged rearward eX- tremity of the tubular work-supporting arm 5 which is formed with two angularly arranged fiat sides 6, 7 (Figs. 7 and 8) and a curved upper side 8, whereby said work-arm is substantially sector-shaped in cross-see tion; Secured to the front or free end of the work-ari'n casting is the throat-plate 9 whose opposite lateral edges are grooved at 10 to slidably receive andv support the end cap 11 which is sector-shaped at its rearward end to conform to the cross-sectional shape of the work-arm. The under surface of the end captapers upwardly and the sides thereof taper forwardly toward the free end of the throat-plate, as shown in Figs. 1 and 12, to facilitate the advance of tubular work about the-work-arm and toward the stitchforming mechanism. v By supporting or hanging the removable end-cap from the for: Wardly projecting throat-plate, the necessity of providing additional slide-pins or hinged slide-bars, such as have heretofore been used, is avoided. The end-cap can thus be made light in weight with. relatively thin walls, and the limited space therewithin and within the work-arm is unobstructed by thickened walls, enlargements, or additional devices necessary for the support of the endcap. The structure is thus materially simplified and improved and is less expensive to manufacture than the various prior constructions with which I am familiar. J ournaled in and crosswise of the standard 2, above the horizontal plane of the work-arm and crosswise of the vertical plane of the work-arm, is the main-shaft 12 carrying a pulley wheel 13 and hand-wheel 1% both cast integral with a common hub 15.

The main-shaft is formed with a ballcrank 16 which is embraced the lower strapped end of a pitman 17 111.6 upper strapped end of which embraces a ball-ended crank-pin carried by the crank-arm 1.8 at the rear end of the needle-actuating rock shaft 19 which is journaled within the bracket-arm 3 and, at its forward end, carries a crank-arm 20 connected to the reciprocating needle-bar 21 by means of the link Secured to the lower end of the needle-bar 21 is the needle-clamp-block 23 which, in the present instance, is socketed to receive four needles n n", n and 97, arranged in a vertical plane transversely of the work-arm 5.

Mounted within the end cap 11, in cooperative relation with the needles, is the threadcarrying looper 2-:t; the upper edge of the blade of which is curved concentrically with the curved upper side of the work-arm, Fig. 3, while the lower edge 24: of said blade is but slightly curved or may even be substantially straight throughout a portion of its length. The slotted shank of the looper is secured to the. looper-support by a screw 26 permitting adjustment of the looper-blade toward and from the stitching plane. The looper-support is clamped to the front end of the oscillating and endwise movable looper-shaft 27 which is journaled within and lengthwise of the work-arm 5 as closely as practicable to the apex of the angle formed by the fiat sides 6 and 7 thereof, Figs. 2 and 8, said angle being large enough to accommodate the necessary loop-seizing and -Slieddi1ig strokes of the looper. It will be understood that this arrangement affords the longest possible radius of oscillation of the looper-blade for a given circumference of the work-arm. In machines of the present character the circumference of the workarm is limited by the size of the smallest tubular articles to be stitched and, in multiple-needle single-looper machines, the longer the radius of oscillation of the looperblade the-greater the degree of certaintywith which the needle-loops will be seized and maintained evenly spaced apart on the looper, as is essential to the formation of a seam of the present character, since the needles in their descent must pass their respec tive previously formed loops without catching or splitting the threads thereof.

It will be seen by referring to Figs. 3 and 10 that the needle-eyes are arranged on an incline; being placed at progressively lower eleva ions beginning with the. needle n to compensate for the upward movement ofthe needles as the looperbeak advances across the space between said needles; the purpose being to insure the passage of the looperbeak at the correct distance above each neelooper-bladc occupies a substantially hori- V zontal or otherwise favorable angular position relatively to the throat-plate.

The looper-shaft 27 carries at its rearward end a crank-arm 28 having a ball-crank-pin 29 which is embraced by the lower strapped end of a link 30 the upper strapped end of which embraces a ball-eccentric 31 on the main-shaft 12 which imparts loop-seizing and -shedding movements to the looper.

The hub of the crank-arm 28 is formed with a rearward extension carrying a ball-ended pin 28 disposed concentrically with the axis of the looper-shaft and embraced by the socketed end of a link 32 whose opposite 'end is connected to the depending arm 33 of a rock-leverfulcrumed to oscillate upon and independently of the cross-shaft 34 j ournaled in the standard 2. The upwardly extending arm 35 of said rock-lever is slotted at 36 to receive an adjustable pin 37 which, through the pitman 38, connects said lever with the eccentric 39 carried by the mainshaft; said eccentric serving to impart sidewise or needle-avoiding movements to the looper.

The feeding mechanism is as follows: secured to the main-shaft is the feed-advancing eccentric 40 which is connected by the pitman 41 to the rocker-arm 42 the split hub 43 of which is clamped to the cross-shaft 34 to which shaft is also clamped the split hubs of the main feed-advancing rocker-arm 44 and the auxiliarv feed-advancing rocker- 35 arm The rocker-arm 44 is formed with a curved slot 48 in which is ad ustably secured a pin 47 connected to one end of a link 46 the opposite end of which is pivotally connected to a lever 49 depending 40 from a fixed fulcrum-pin 50 which extends across and within the standard 2 in paral lelism with the main-shaft 12. The lower end of the lever 49 is pivotally connected to the rearward end of the main feed-bar 51 which extends within and longitudinally of the work-arm, and, at its carries a screw-pin 52, Fig. 4, which passes through the slotted shank 53 of the main feed-dog 54 and serves to secure the latter forward end,

to said bar while permitting adjustment of the feed-dog lengthwise of said bar.

The auxiliary feed-rocker 45 is formed with a curved slot 55 in which is fitted a pin 56 carried by the rear end of a link 57 the 55 front end of which is pivotally connected to a lever 58 depending from the fulcrum-pin 50. The lower end of the lever 58 is pivotally connected to one end of a link-section 59, the opposite end of which carries a fixed 60 pin 60 and a screw 61, both extending through the slot 62 in the rear end of the link-section 63, the front end of which is pivotally connected at 64 to a bracket 65 screwed to the side of the auxiliary feed- 65. bar 66 which is deeply recessed o1- grooved at its under side, Fig. 8, to fit about and slide upon the forward end-portion of themain feed-bar 51. The feed-bar (36 carries the auxiliary feed-dog 67'.

The fulling feed may be readily adjusted while the machine is in operation by means of the treadlecontrolled lever-arm 68 which is mounted 011 the rock-shaft (39 fulcrumed in the standard 2 and carrying a lever-arm 68 which is connected by the link 70 to the link 57. Adjustable stop-screws 71 and 72 are provided to limit the range of movement of the lever-arm 6S and a spring 7 3 connected to the lever-arm (38 and to the frame serves to return the parts to normal posi:

.tion when pressure upon the treadle is re leased.

The main and auxiliary feed-bars are supported within the work-aim on a fulcrumblock 7 4 which is fitted within the slot 7 5 in the main feed-bar and is carried by the fulcrum-pin 7 6 supported, in turn, at the forward end of the feed-lifting lever 7 7 which is pivoted within the work-arm on the trunnion-screws 78, 78. The said lifting lever 77 is rocked by means of the eccentric 78, Fig. 4, carried by the main-shaft and embraced by the upper strapped end of a pit man 7 9 the lower end of which is pivotally connected to a rearward extension of said feed-lifting lever.

Having thus set forth the nature of the invention, what I claim herein is:

l. A sewing machine comprising, in combination, a frame including a work-supporting arm which is substantially sector-shaped in cross-section, and stitch-forming and work-feeding mechanisms incoiporated in said frame.

2. A sewing machine comprising, in combination, a frame including a tubular worksupporting arm free at one end and formed with two substantially flat sides arranged at an angle to one another and a third curved side merging into said fiat sides, whereby said arm is substantially sector-shaped in cross-section, and stitch-forming mechanism incorporated in said frame and including an oscillating looper sustained at the free end of said arm.

3. A sewing machine comprising, in combination, a frame including a tubular worksupporting arm having two substantially flat sides arranged at an angle to one another and a third curved side joining the diverging edges of said flat sides, whereby said arm is substantially sector-shaped in cross-section, and stitch-for1ning mechanism incorporated in said frame and including an oscillating looper-shaft journaled within and lengthwise of said arm adjacent the apex formed at the juncture of said flat sides.

4. A sewing machine comprising, in eombination, a frame including a tubular worksupporting arm free at one end and formed with two substantially flat sides arranged at an angle to one another and a third curved side merging into said flat sides, whereby said arm is substantially sector-shaped in cross-section, stitch-forming mechanism incorporated in said frame and including an oscillating looper sustained atthe free end of said arm, and feeding mechanism extend ing within and lengthwise of said arm.

5. A sewing machine comprising, in combination, a frame including a tubular worksupportingtarm free at one end and formed with two substantially fiat sides arranged at an angle to one another and a third curved side merging into said fiat sides, whereby said arm is substantially sector-shaped in cross-section, stitch-forming mechanism incorporated in said frame and including an oscillating looper sustained at the free end of said arm, a looper shaft Within said arm and differential feeding mechanism including main and auxiliary feed-bars arranged within and lengthwise of said arm and above said looper-shaft.

6. A sewing machine comprising, in combination, a frame including a tubular worksupporting arm free at one end and formed with two substantially flat sides arranged at an angle to one another and a third curved side merging into said flat sides, whereby said arm is substantially sect0r shaped in cross-section, and stitch-forming mechanism incorporated in said frame and including a plurality of needles disposed in a plane transverse to said arm, and an oscillating looper of relatively long radius sustained at the free end of said arm and cooperating with said needles to form stitches.

7. In a sewing machine, in combination, a frame including a hollow work-supporting arm, a throat-plate secured at thefree end of said arm and projecting forwardly there of, a removable end-cap slidably supported by said throat-plate, and. stitcl1f0rming mechanism incorporated in said frame and including a looper housed within said endcap.

8. In a sewing machine, in'combination, a frame including a hollow work-supporting arm, a throat-plate secured at the free end of said arm and projecting forwardly thereof, a removable end-cap hung from said throat-plate, and stitch-forming mechanism incorporated in said frame and including a looper housed within said end-cap.

In testimony whereof, I have signed my name to this specification.

GEORGE S. GATCHELL.

copiel of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G. 

